Abstract: Openings in a mammalian body made by any medical procedure or non-medical event are sealed with a bioabsorbable plug or sewn with a bioabsorbable suture. In one exemplary embodiment, the plug in dehydrated, unexpanded condition is pushed by a pushing device through the lumen of a needle until a first part of the plug is external to the opening and a second part is internal to the opening. The needle is then withdrawn while the position of the pushing device is maintained. The pushing device is then withdrawn, leaving the plug in sealing relation to the opening. The body's moisture causes the plug to expand to complete the sealing of the opening, or the expansion may be caused by exposure to air, light, or other stimulant. The opening may be formed in soft tissue, internal organs, or hard tissue. The plug seals the flow of liquid or gaseous biological fluids.